Method of marking enameled ware.



W. J. KOHLER.

METHOD OF MARKING ENAMELED WARE APPLIIEATION FILED JAN. 6. 1916.

1,290,580. Patented Jan. 7,1919.

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I v I UNITED STATES PATENT orrrcn.

WALTER J. KOHLER, OF S HEBOYG'AN, WISCONSIN, ASSIGNOR TO KOHLER 00., 0F KOHLER, WISGONSIN,'A CORPORATION OF WISCONSIN.

METHOD OF MARKING ENAMELED WARE.

Specification of Letters Patent.

'Patented J an. '7, 19.1.9.

To all whom it may concern:

Be it known that I, WALTER J. KOHLER, a citizen of the United States, and resident of Sheboygan, in the county of Sheboygan and State of Wisconsin, have invented'new and useful Improvements in Methods of Marking Enameled Ware, of which the following is a description, reference being had to the accompanying drawings, which are a part of this specification.

This invention relates to the art of manufacturing enameled ware such as bath tubs, lavatories and the like enameled iron plumbing ware, and has for its object to produce a permanent mark in the exposed enameled surface by which a particular grade or brand of ware may he identified and distinguished from others.

Many unsuccessful attempts have been made in an experimental way to devise a means for permanently marking enameled iron ware other than by the usual markings in the castings in obscure places which are inaccessible after installation. Such attempts have included the impression of the mark in the enamel. The coloring in fine grade enamel ware is so even and uniform, and in the case of bath tubs extends over so great a surface that a slight departure therefrom may stand out conspicuously and detract from the appearance of the article. On the other hand, a marking which produces an irregularity in the smooth, glazed surface, either by raising or depressing the surface to the slightest extent, is objectionable as being too noticeable and appearing as a flaw in the finish of the article. It also involves manufacturing difiiculties and forms a dirt catcher.

The method of marking constituting the present invention avoids these objections and enables the mark to be made distinct or as faint as desired and still of uniform depth of tint throughout and with no irregularity in the uniformly smooth surface of the enamel so as to be inconspicuous and unnoticeahle and only apparent upon careful inspection.

With the above and other objects in the invention consists in the method of permanently marking enameled ware as erein claimed and all equivalents.

Referring to theaccompanying drawing,

view

in which like characters of reference indidicate the same'parts in the different views,

Figure 1 is a view of an enameled plate having a mark thereon consisting of the letter O and representing the preferred appearance of the mark as produced by the process of this invention;

Fig. 2 is a sectional View of such plate on the line, XX of Fig. 1, provided with the ground coat preparatory to enameling, the depth of coating in this and other sectional views being exaggerated for clearness of illustration Fig. 3 is a similar view after the first application of powdered enamel;

Fig. 4 is a similar view after firing the first coat of enamel;

Fig. 5 is .a similar view after applying the second coat of powdered enamel;

Fig. 6 is a similar view after applying a I light deposit of powdered enamel of substantially the same composition but of slightly different color and in the shape of the mark to be produced; and,

Fig. 7 is a similar View of the finished product after firing the second .coat of enamel, and showing the marking enamel embodied therein at its surface.

The marking process of the present invention relates more particularly to the art of enameling by what is known as the dry process, in which the enamel is applied in a powdered form to the metal body when the latter is at a heat of approximately 1800 degrees Fahrenheit, and is then fused in a furnace. As shown in Fig. 2 the surface of the metal 10 is first given a ground coat 11 as usual of a material which will unite with the metal and with the enamel, and then the metal is heated to a white heat. While the metal is hot a layer of powdered enamel 12 is dusted thereon, as shown in Fig. 3, and it is returned to the furnace to fuse the coat of enamel, as shown in Fig. 4. Then a second layer of powdered enamel 13 is deposited on the fused enamel surface while the article is still hot. When this is of the desired depth, even and smooth throughout the surface of the article, and is ready to be re turned to the furnace for the final reheating a very .light line of powdered enamel 14 is gently deposited on the layer of powdered enamel 13 in any. suitable manner that will insure an even deposit along the lines of the mark only. The powdered enamel 14 for producing the mark is of the same or similar composition and fuses at approximately the same temperature as the enamel used in producing the coatings 12 and 13 but has a furnace for the final firing, and when removed the lines of marking enamel have become fused with the enamel surface 13 and incorporated therein, with an even, smooth surface showing no irregularity or undula-tion by reason of the original increased depth of powdered enamel along Ithe lines of the mark.

The mark thus produced in the enamel surface is incorporated in the enamel itself and is, therefore, permanent. It is sufficiently distinguishable for trade mark or identification purposes without affecting the finish or general appearance of the enameled surface and may be made so faint as to not be unduly noticeable.

Though the marking process of this invention is described as applied to the dry enameling rocess involving two' coats of enamel it is of course applicable to the onecoat dry process or to processes involving any number of coats, the object being to incorporate the marking enamel in one of the later coats, preferably in the final coat.

Any suitable means may be employed for depositing the powdered marking enamel on the layer of powdered surface enamel.

\Vhat I claim as new and desire to secure by Letters Patent is:

1. The process of marking enameled ware which consists in fusing together a. layer of -iowde ce enamel and. superimposed 1 marking enamel.

of producing marked enue h consists in covering the article with a layer of powdered surface enamel and depositing on such layer of powdered enamel marking lines of powdered enamel of different color from the powdered surface enamel and heating the articles to fuse the enamel.

3. The process of producing permanently marked enameled ware without undulations in the enameled surface, which consists in covering the heated article with a coating of powdered surface enamel and gently depositing on such layer of powdered enamel lines of powdered marking enamel differing slightly from the powdered surface enamel and subjecting the article to heat to simultaneously fuse the powdered surface enamel and the powdered marking enamel to cause them to unite to form a smooth surface with a difference of color indicating the presence of the marking enamel.

4. The process of producing marked enameled ware which consists in roviding the article with a ground coat of binding material heating the article to a white heat and applying a coat of powdered enamel, again heating the article to a white heat to fuse the firstcoat of enamel, and while hot applying thereto a second'coat of powdered enamel and depositing on said second coat of powdered enamel before reheating lines of marking enamel differing in color from the other powdered enamel and again heating the articl to fuse the second coat of powdered enamel and the lines of marking enamel to a smooth enameled surface only indicating the presence of the marking enamel by the difference in color thereof along the lines of its application.

5. An article of manufacture having an enameled surface with a distinguishable mark incorporated therein, such mark being formed of enamel of different color from the other enamel. the two enamels forming a perfectly smooth surface without relief or depression to show the presence of the mark.

in testimony whereof, E afiiz-i my signature, in resence of two witnesses." I

, XVl-LLTER J. HOHLER.

Witnesses U. A. Knoos, GEORGE lfifE'iEB. 

